This invention relates to a thrust producing shoe sole and heel suitable for use on shoes designed for men, women and children, and more particularly, to a shoe sole and heel having resilient bulges in the heel portion and in the metatarsal ball area of the sole portion.
The resilient bulges extend below the bottoms of the heel portion and metatarsal ball area of the sole, and thus in standing and walking come in contact with the walk surface. The bulges are defined by resilient bottom walls of cavities in the heel portion and sole portion of the sole and heel, and the two cavities are connected by a restricted passageway. The cavities and restricted passageway contain fluid, either gas or liquid, in such pressure and amount as to create the aforesaid bulges.
When at rest, the foot of a wearer of the sole and heel of the invention is cushioned comfortably on the pressurized fluid in the bulges, and in walking fluid under bulge producing pressure alternates through the passageway between the heel portion and metatarsal ball area bulges, producing shock absorption and an alternate lifting effect by the bulges which provides forward thrust, both in the heel portion and in the metatarsal ball area, that facilitates walking.
Applicants have conducted a prior art investigation of pertinent U.S. patents, and list the following as known to them: U.S. Pat. Nos. 508,034; 2,605,560; 547,645; 2,863,230; 586,155; 3,044,190; 850,327; 3,871,117; 1,605,985; 4,071,963. Copies of these patents are being filed with this application.
The prior patents above cited disclose shoe soles and heels embodying pneumatic or hydraulic features of one kind or another, but applicants find that no one of them is directed to a thrust producing shoe sole and heel such as here disclosed and claimed.